1. Field of the Invention
The invention described herein is generally related to improvements in a process for manufacturing a corrugated box, and more particularly to methods and apparatus used in scoring such corrugated boxes.
2. Statement of the Prior Art
"Scoring" is a process which is known in the art of boxmaking for its ability to make folds in a box. For example, a square or rectangular box requires four scores to make its four folded corners. A hexagonal-shaped box, on the other hand, requires six scores to make its six folded corners. In any case, it can be readily appreciated that the scores of a box must be parallel in order to provide an assembled box with straight sides. Scores that are not parallel to one another lead to misshapen, commercially undesirable products. It has, therefore, been an objective in box scoring apparatus of the prior art to provide boxes with accurately spaced, parallel scores.
Known bar scoring apparatus have typically employed multiple scoring presses to achieve such accuracy. However, such multi-bar scoring apparatus have suffered from two disadvantages. First, multi-bar scoring apparatus must employ a complex score bar mechanism for each desired score on a box. The maximum number of scores that can be applied to a box and the minimum spacing between adjacent scores is a function of the mechanical design of the score mechanisms and is therefore limited by the available space. In addition, the simultaneous application of the multiple bar scores, which is the normal procedure, does not permit the material between scores to yield and stretch, thereby frequently causing fractures to occur. Second, since the available force must be distributed over a variable number of scores, the unit pressure at each score will therefore vary accordingly, thus leading to variability in the end product. Variations in pressure most often exist from point to point along the box with multi-bar scoring apparatus. Accordingly, it would be desirable to provide bar scoring apparatus which do not suffer from these disadvantages.
One approach that has been utilized in the art of metal working to provide a number of successive parallel bend lines in corrugated metal plate is disclosed in U.S. Pat. No. 4,603,572. (VanBrenkelen et al.). With such apparatus, a corrugated metal plate is fed through a scoring press having a pair of opposed press beams which form a bend line accurately without deformation in the corrugated plate. After one bend line is made, the corrugated plate is incremented along a substantially horizontal feeder table to a position for the next bend line to be made. Complex mechanisms are required to maintain the corrugated metal plate in alignment. Therefore, it can be readily appreciated that the use of such apparatus to make multiple, successive, parallel folds in a box would unnecessarily complicate the manufacture of such boxes and increase the cost of such manufacture.